Finding the Fourth Proportional to 1,556.17, 2,147.59 and 857.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,556.17 : 2,147.59 = 857.55 : x
2. Step 2: Convert to fraction form
   1,556.17/2,147.59 = 857.55/x
3. Step 3: Cross multiply
   1,556.17x = 2,147.59 × 857.55
4. Step 4: Simplify right side
   1,556.17x = 1,841,655.07
5. Step 5: Solve for x
   x = 1,841,655.07/1,556.17
6. Step 6: Final answer
   x = 1,183.45